Endocrine Abstracts

Nonautoimmune hyperthyroidism (NAH) due to activating mutation of the TSH receptor (TSHR) gene is extremely rare. We report 4 unrelated families with NAH experienced for the last two years in Kumamoto Prefecture, Kyushu, Japan. TSHR gene mutation site of these four families are all the same: p.Asn406Ser (heterozygous). Thyroid functions observed in these families were subclinical hyperthyroidism or overt hyperthyroidism except for one case with euthyroidism. Thyroid autoantibo...